The Germans throw their Tyrolean hats into the ring and go after proxy servers …

Last night, German authorities raided seven data centers in search of child pornography trafficking or evidence thereof, seizing a total of ten servers in the process. This would be a routine incident in the worldwide battle against underage porn distribution, if not for the fact that some of these machines were running TOR anonymyzing proxy servers, and nothing else.

TOR is an "onion routing" system, where a directory server points your traffic to a middleman node that can pass it on to other middlemen or to an exit node. The exit node finally connects to the site you're trying to reach, and the data is sent back through the system of middleman tunnels. Every step of the way is encrypted, except for the final exit node to the content server connection. That makes the exit node show up in server logs as the connecting party, and it's probably why the German police thought that the confiscated servers had been looking at naughty images.

The TOR network seems resilient, however. At the moment, only 20 of 787 TOR exit nodes appear to be offline or hibernating, with 5 of the unreachable nodes inside German IP address space. 180 German exit nodes remain in operation. While the seized servers are out of operation, others seem to be picking up the slack.

TOR's default settings don't leave any logs usable for tracking down any individual user's actual site usage—two separate settings have to be changed in order to generate logs with that level of detail. That makes them unlikely targets for legal probes, because there's just not much to look at in most cases. TOR executive director Shava Nerad told Ars that the service has not been implicated in any child porn wrongdoing, and expects the servers to be returned shortly.

TOR server operators in Germany appear to have formed an ad hoc support network to keep each other informed of what's happening, and it looks like the raid may have an unintended effect: server operators have upped their traffic allowances, and some have donated money to the TOR project in response to this action.

TOR seems to be doing a decent job of keeping user traffic secure and untrackable, and if anything, this case might just raise public awareness of its existence. The blogger who originally broke this story is now keeping a current roundup of recent developments, if you want to stay up-to-date.